Sunday, February 26, 2012

You Cannot Eat Money

When all the trees have been cut down,
when all the animals have been hunted,
when all the waters are polluted,
 when all the air is unsafe to breathe,
 only then will you discover you cannot eat money.

- Cree Prophecy

The economy is based on an imaginary entity; it is a currency called money.  While it makes sense to have a currency whereby goods and services can be easily exchanged, this modern method of trade allows us to forget that money, in and of itself, is worthless.  The quotation above illustrates this notion with absolute clarity.

Modern society is so far removed from a time when one's needs to survive and prosper were met through direct action (the collection of one's own food and shelter).  To be clear, I have no desire to turn back the technological clock to a time when societies did not enjoy the benefits of divided labour.  But it is helpful to consider the hunter gatherer way of life, if only to allow us to correctly identify what matters.

Going on a camping trip is a great way to briefly escape the economic landscape, and to accurately reflect on what we truly value.  I actually tried ice fishing for the first time this past weekend, and in my group of four, we caught three small fish collectively over the course of many hours.  Without modern agriculture, and environmental conditions in which it can thrive, we would all be screwed.

Saturday, February 18, 2012

Vanier College Robotics Club Gives me Hope

I tend to keep the college at which I teach and this blog on which I write as separate entities, as there is no actual affiliation between the two.  But I am a mentor for the Vanier Robotics Club "Build Team", and today, I really want to praise them and the entire Vanier Robotics Club for their accomplishments over the past four months.  I urge adults who fear that today's youth have become lethargic to read on.

Vanier College hosted Profuga 2012, the 11th edition of the CRC Robotics competition, inside its Sports Complex over the past three days (Thursday, Feb 16 to Saturday, Feb 18).  The annual provincial competition is run by a company called CRC Robotics.  On their website, they describe themselves and the competition as follows:

"CRC Robotics is a non-profit organization offering high-school and CÉGEP students a quality multidisciplinary competition in an entertaining, high-intensity environment to counter school dropout rates by inspiring tomorrow's leaders. Students are challenged to build a robot and to produce a video, web site, and kiosk presentation, where all tasks are entirely student-run."

This year's robotics challenge was ultimately a series of two-on-two capture the flag heats, where schools alternate who they compete against as well as alongside.  The terrain on which the robots did battle had ramped surfaces.  Designing a robot that can not only manipulate objects, but do so while translating up or down a 20 degree incline is no easy task.  However, the tech-savvy students composing the Vanier Build Team and those of tens of other schools were up to it.

It may surprise you to learn that the goal in this competition was not to chop other robots to bits with buzz saws or axes (I must admit that this was the particular image I used to associate with robotics competitions). But there are a couple of reasons why, in my view, a relay-race or capture the flag is a much better choice than a battle to the death for this particular competition:

(1) The event is longer when robots don't get sawed in half.
(2) Canada in general (and the province of Quebec in particular) has a fairly pacifist mindset.  

Sunday, February 12, 2012

"Speed", Featuring Keanu Reeves and Mechanics

The 1994 action thriller Speed introduced America to two soon-to-be movie stars in Keanu Reeves and Sandra Bullock.  The film contained all of the escapist elements that a summer outing to the theatre is supposed to: adrenalin-fuelled intimacy between the two leads, a smart yet mentally deranged villain, and lots of things that can and eventually do go boom. 

Yet, after the credits role, and the movie goers make their way home, the images that stick with them are not those of kissing, lunacy, or explosions, but rather the exciting set-pieces involving mechanics that are continuously on display.  From the elevator on which the film opens, to the bus, where the majority of it takes place, to the subway on which it concludes, it feels like a 116-minute mechanics course, albeit an entertaining one.  I don't know this for a fact, but I would suspect that director Jan de Bont took a physics class as a kid and enjoyed it immensely.

I suppose it is not surprising that the movie features mechanics, as its title is a key term of kinematics - speed is defined as the magnitude of velocity.  And, when an ex-cop turned psycho attaches a bomb to a city bus, he programs it with this kinematic parameter in mind: the bomb is armed once the bus surpasses a speed of 50 mph, and is set to blow should it ever fall below this value again.

If there were more class time in the Mechanics course that I teach, I would actually show Speed in class.  And, after each action sequence, I would pause the film to discuss the key concepts of mechanics on display, and even solve explicitly for some of the unknown parameters.  As this exercise is quite time-consuming, I simply encourage my students to try this activity on their own.

In the first scene alone, many aspects of mechanics are highlighted when an elevator filled with innocent people threatens to plummet to the ground.  The periods of free fall experienced by both the elevator and those inside begs several questions, like "Should the passengers float upwards?" and "Would they increase their likelihood of survival if they jumped just before the cabin hits the ground?"  I'll leave readers to consider these on their own.

When the cabin and its contents are supported by a single rope, how much tension manifests inside it?  Does the rope extend, and if so, by how much?  Why does the supporting crane above break?  I'll answer this last one: the tension in the cord creates a large moment (or torque) about the support structure.  The bending moment leads to a local stress that is larger than the ultimate stress value of the material making up the structure.

We could go on and dissect the mechanics of the entire film in this fashion, but instead, I would like to focus on two particular action sequences in some detail.  These two sequences occur on the fast-moving bus, and I always discuss them with my mechanics classes.

Friday, February 3, 2012

Guinness Book of World Records a Useful Resource

One of the first books I ever bought, The Guinness Book of World Records - 1992 edition, is still, in my mind, the most informative and entertaining among those that sit on my book shelves.  Where else can one turn to when they want to know the height of the tallest person (8' 11", Robert Waldo), the maximum combined length of finger nails on one hand (181 inches, Shridhar Chillal), and the maximum g-force experienced by any bird (10g's, when the red-headed woodpecker strikes a tree)?

Well, I suppose one could turn to Google, but performing such searches would be much more arduous.  Also, no one would even think to search for most of the endeavours described in the Guinness Book.  In fact, much of the fun in flipping through this record book is had by marveling at some of the most bizarre records it contains, such as the longest leapfrogged distance (888.1 miles by 14 members of a high school class during a 189-hour and 49-minute span).   

From business to the arts, science to sports, anything that has a maximum or minimum is likely captured within those 833 pages.  And, I would go so far as to say that The Guinness Book of World Records is a vital tool for all engineers.  Let me explain...